ANTI-LOCK BRAKE SYSTEM ABS Warning Light Remains ON

DESCRIPTION

The skid control ECU (brake actuator assembly) is connected to the combination meter via CAN communication.

If any of the following is detected, the ABS warning light remains on:

• The skid control ECU (brake actuator assembly) connectors are disconnected from the skid control ECU (brake actuator assembly).

• There is a malfunction in the skid control ECU (brake actuator assembly) internal circuit.

• There is an open in the harness between the combination meter assembly and the skid control ECU (brake actuator assembly).

• The ABS control system is defective.

• The voltage at terminal IG is high.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK CAN COMMUNICATION SYSTEM

   
   

   1. Check if CAN communication system DTCs are output Click here.

      Result

      Result	Proceed to
      DTC is not output	A
      DTC is output	B

   
   

   B

   GO TO CAN COMMUNICATION SYSTEM Click here

   A

2. CHECK IF BRAKE ACTUATOR ASSEMBLY CONNECTOR IS SECURELY CONNECTED

   
   

   1. Check if the skid control ECU (brake actuator assembly) connector is securely connected.

      OK
      The connector is securely connected.

   
   

   NG

   CONNECT CONNECTOR TO ECU CORRECTLY

   OK

3. INSPECT BATTERY

   
   

   1. Inspect the battery voltage.

      Standard voltage
      20 to 28 V

   
   

   NG

   CHECK OR REPLACE CHARGING SYSTEM OR BATTERY Click here

   OK

4. CHECK HARNESS AND CONNECTOR (IG TERMINAL)

   
   

   1. Turn the ignition switch off.

   2. Disconnect the skid control ECU (brake actuator assembly) connector.

   3. 

      Text in Illustration

      *a	Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly))

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition B9-34 (IG) - Body ground Ignition switch ON 20 to 28 V

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR (IG CIRCUIT)

   OK

5. CHECK HARNESS AND CONNECTOR (GND1, GND2 TERMINAL)

   
   

   1. Turn the ignition switch off.

   2. 

      Text in Illustration

      *a	Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly))

      Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition B9-1 (GND1) - Body ground Always Below 1 Ω B9-13 (GND2) - Body ground Always Below 1 Ω

   3. Reconnect the skid control ECU (brake actuator assembly) connector.

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1, GND2 CIRCUIT)

   OK

6. READ VALUE USING INTELLIGENT TESTER (ABS WARNING LIGHT)

   
   

   1. Warm up the engine.

   2. Turn the ignition switch off.

   3. Replace the normal DLC3 cable (12 V specification) for the intelligent tester with the 24 V DLC3 cable.

      Note

      Be sure to use the 24 V DLC3 cable when connecting the intelligent tester to the DLC3. Using the normal DLC3 cable (12 V specification) will cause damage to the tester.

   4. Connect the intelligent tester to the DLC3.

   5. Turn the ignition switch to ON.

   6. Turn the intelligent tester on.

   7. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

   8. According to the display on the intelligent tester, read the Data List.

      ABS/VSC/TRC

      Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
      ABS Warning Light	ABS warning light / OFF or ON	OFF: Warning light OFF ON: Warning light ON	-

   9. Check the intelligent tester display condition of the ABS warning light.

      Result

      Result	Proceed to
      Display of the Data List remains OFF.	A
      Display of the Data List remains ON.	B

   
   

   NG

   REPLACE BRAKE ACTUATOR ASSEMBLY Click here

   OK

   GO TO METER / GAUGE SYSTEM Click here